The class of polymers of carbon monoxide and olefins has been known for some time. U.S. Pat. No. 2,495,286 (Brubaker) discloses such polymers of relatively low carbon monoxide content in the presence of free radical initiators, e.g., peroxy compounds. G.B. No. 1,081,304 discloses similar polymers of higher carbon monoxide content in the presence of alkylphosphine complexes of palladium compounds as catalyst. U.S. Pat. No. 3,694,412 (Nozaki) extended the reaction to produce linear alternating polymers in the presence of arylphosphine complexes of palladium moieties and certain inert solvents.
More recently, the class of linear alternating polymers of carbon monoxide and at least one ethylenically unsaturated hydrocarbon, now becoming known as polyketones or polyketone polymers, has become of greater interest. U.S. Pat. No. 4,880,903 (VanBroekhoven et al.) discloses a linear alternating polyketone terpolymer of carbon monoxide, ethylene, and other olefinically unsaturated hydrocarbons, such as propylene. Processes for production of the polyketone polymers typically involve the use of a catalyst composition formed from a compound of a Group VIII metal selected from palladium, cobalt or nickel, the anion of a strong non-hydrohalogenic acid and a bidentate ligand of phosphorus, arsenic or antimony. U.S. Pat. No. 4,843,144 (VanBroekhoven et al.) discloses a process for preparing polymers of carbon monoxide and at least one ethylenically unsaturated hydrocarbon using the preferred catalyst comprising a compound of palladium, the anion of a non-hydrohalogenic acid having a pKa of below about 6 and a bidentate ligand of phosphorus.
The resulting polymers are relatively high molecular weight materials having established utility as premium thermoplastics in the production of shaped articles, such as containers for food and drink and parts for the automotive industry, which are produced by processing the polyketone polymer according to well known methods. For some particular applications it is desirable to have properties which are somewhat different from those of the polyketone polymers. The more desirable properties of the polyketone polymers may be retained, and yet other properties improved, through the provision of a filled polymer compound. Reinforcing a polymer with a filler often provides a less expensive product, in addition to desirable properties for various applications.
Mineral-filled polyketone compounds with certain desirable properties are disclosed in U.S. Pat. No. 4,851,470 (George). The neat polyketone polymer has an unfortunate tendency to form chemical crosslinks at melt processing temperatures, as evidenced by a steady increase in melt viscosity as the polymer is processed. Mineral fillers frequently possess a variety of ionic species which are capable of intensifying melt processing problems for the polyketone polymer, such as accelerating crosslinking of the polymer, thereby limiting the melt processability of the filled polyketone compounds.
It is an objective of this invention to provide a filled polyketone polymer compound that exhibits little or no viscosity increase during melt processing. The filled polyketone polymer compounds of the subject invention exhibit viscosity levels during processing that are unexpectedly lower than the viscosity levels typical for compounds filled with commonly used commercial fillers, and yet exhibit mechanical properties at least equal to those of compounds filled with such commercial fillers.